Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net loss	$ (1,817)	$ (3,911)
Reconciliation of net loss to net cash provided by operating activities:
Depreciation and amortization	1,075	966
Stock-based compensation expense	845	475
Changes in operating assets and liabilities:
Accounts receivable	(145)	903
Inventories	409	(314)
Prepaid expenses and other current assets	(240)	(391)
Other non-current assets		18
Accounts payable	(805)	1,873
Accrued expenses and other	(335)	(616)
Deferred rent	(18)
Deferred revenue	1,522	1,519
Net cash provided by operating activities	491	522
Investing activities:
Purchases of property and equipment	(1,404)	(1,202)
Net cash used in investing activities	(1,404)	(1,202)
Financing activities:
Proceeds from loan facility	954
Proceeds from equipment loans	1,501
Principal payments on debt	(1,143)	(122)
Dividends paid	(7)	(14)
Net cash provided by (used in) financing activities	1,305	(136)
Effect of exchange rate changes on cash and cash equivalents	78	(110)
Net increase (decrease) in cash and cash equivalents	470	(926)
Cash and cash equivalents, beginning of period	20,994	13,901
Cash and cash equivalents, end of period	21,464	12,975
Supplemental cash flow information
Cash paid for interest	50	$ 44
Supplemental noncash information
Purchases of equipment through accounts payable and accrued expenses	327
Series C Preferred Stock [Member]
Supplemental noncash information
Excess of carrying value of Series C Preferred Stock over redemption value	459
Redemption of Series C Preferred Stock and dividend included in accounts payable	$ 98